Congressman William Lacy Clay of Missouri has filed a federal lawsuit against Architect of the Capitol Stephen Ayers for removing a student painting from a Capitol Hill exhibition, claiming that he violated the artist’s right to free speech, Spencer S. Hsu of the Washington Post reports.

The lawsuit is the latest development in an ongoing controversy over an exhibition of works by high school students who won an annual nationwide art competition sponsored by the Congressional Institute. David Pulphus’s painting depicts police officers, who resemble razorback pigs in uniforms, aiming weapons at African American protesters in a standoff that was inspired by the protests in Ferguson, Missouri, following the shooting of unarmed African American teen Michael Brown in 2014.

Clay said that the removal of the painting “sent a chilling message to young Americans that their voices are not respected.” He added, “This case is truly about something much bigger than a student’s painting. It is about defending our fundamental First Amendment freedoms which are currently under assault in this country.”

The work was taken down several times over the course of a week by various people, including Republicans Doug Lamborn of Colorado, Dana Rohrabacher of California, and Brian Babin of Texas, who claim that the work violates the rules of the competition, which state that “depicting subjects of contemporary political controversy or a sensationalistic or gruesome nature are not allowed.” Clay repeatedly rehung the work, which had been on display for seven months before “the unprecedented step of retroactively disqualifying” a contest winner.

In mid-January, Ayers stepped in and ordered the permanent removal of the painting. Clay said the Architect of the Capitol, whose office is in charge of maintaining and preserving the buildings, gardens, monuments, and artworks on Capitol Hill, chose to censor Pulphus’s artwork “in response to the enormous political pressure he experienced from the Speaker of the House and certain right-wing media outlets.”

Ayers, who was appointed by Barack Obama in 2010, has seven days to respond to the suit. The painting is now hanging in Clay’s office.